I'm running Jenkins on GKE with the Kubernetes plugin. I added a postgres container as a sidecar with the jnlp agent container. It's reachable on localhost:5432 from the agent. I also mount the GKE node's Docker socket and bin in the agent so I can spin up "sister" containers. This is also working fine.
Now I want to do the following:
pipeline {
stages {
stage('pytest') {
agent {
docker {
image "<image created in a previous stage>"
args '--add-host=database:\$(hostname\\ -i)'
}
}
steps {
// use postgres in sidecar of jnlp agent
// e.g. on `database:5432`
}
}
}
}
Doing this manually works great, but in Jenkins the above fails with:
Error: invalid argument "database:$(hostname -i)" for --add-host=database:$(hostname -i): invalid IP address in add-host: "$(hostname -i)"Does anyone have an idea on how to escape the above? Or perhaps a completely different way of approaching this problem?
I don't have Docker 18.03+ available on GKE (stuck at 17.03.2-ce) so I can't do host.docker.internal
docker run --network host does nothing either.
If it's a sidecar you don't need $(hostname) you should be able to connect with localhost:5432. Containers in pods share the same address space.
Another option is to use initContainers in your pod spec to set up the file that you want. You can write a bash script like this:
#!/bin/bash
cat <<EOF
pipeline {
stages {
stage('pytest') {
agent {
docker {
image "<image created in a previous stage>"
args "--add-host=database:${HOSTMAME}"
}
}
steps {
// use postgres in sidecar of jnlp agent
// e.g. on `database:5432`
}
}
}
}
EOF > /your-config-file
${HOSTNAME} being the environment variable in the pod.